Spool and method for its manufacture



D .25,1934- 1G, BAXENDEN HAL 1,985,160

SPOOL AND METHOD FOR ITS MANUFACTURE Filed Aug. 21, 1931 g M W 2:9

- Aijg's Patented Dec. 25, 1934 Thomas: George 'Baxenden,watford, andJohn Bobert-Collyear,:Bnshey,jEngland This invention relateszto theconstruction and methods for their. manufacture :of spools such,

for examplaas those which areusedrior photographic films inroll-filmscamerasandt'theilike although. the construction hereindescribed .is applicable-to spoolsior other purposes andzthe inventionhas for'its object to devisea spool ineluding its-methodof...manuiacture ;which. shall be easier to. construct and cheapertomanufacture than the constructions hitherto. in. use"; but whichshall, nevertheless -be oi suflicient. rigidity and mechanical strengthfor the: purpose for which it is to be used. H H 1 The invention relatesmore particularly to that type of spool which consists ofa hollow;tubular spindle or barrehto the ends oiwhich, or-near which serve toguideand retainzithe material, such as photographic film, as :itistwound icn the spool, although the construction isalso. applicable oropenings in; each end disc, arranged *in the form of a circle ofa'diameterapproximately equal to or larger than-the diameter of thebarrel, the outer edges of s'aidslotsbeing turned over by theshearingoperation in order -to'allow the end of the barrel to be slippedth'erethrough; and

then forcing the turned-over edges Ofthe-openings or slots back to theiroriginal; positionsin the plane of the'disc and thus gripping the barreltightly. Obviouslythe end of the barrel need nctbe flared butcan retainits-original diameter in whichcase-the end is suitably-Pout to fit intothe slots. By this method the end discs are securely held in theircorrect position on the barrel without any additional security in theway of welding or the like. I

In the above construction it should be noted that no metal is removedfrom the end discs in forming the openings or slots, the latter beingformed by shearing the metal along one edge of a slot and simultaneouslyturning back the metal occupying the position of the slot so as to formthe required opening or slot.

A further feature of the invention consists in providing a constructionof key stop which is clamped in position with one of the end discs.

In a modification of. the above arrangement thenslotsare replacedsbytacentral hole formed hin each end disc,.=of @a diameter slightly lessthan l the external diameter of: the barrel, the edge moi this hole isthen turned over to allow the end not: thebarrel to be passedtherethrough andthe a turned over -sedge. isnthen forced back to itsaoriginalnposition:sothat it grips the barrel and secures the endvdiscsfirmly. in position.

1iInathis construction also no metal, apart from the: cutting" of thecentral hole, is actuallyre cmoived in.securingran enddisc the edge ofthe =centralh0le in :the latter being turned back out then returned toits original position.

---of the way to a'llow the barrel to be inserted, and

l "i'l his latter construction -is particularlyapplicableto-spoolshavingsolid spindles. the ends of which,areattachedmet'alrend discs I- he methods-yof -construction will be more-cleetrly.wunderstoodby reference to-the accomnpanying drawing whichshows the constructions of photographic film-spools'for use in roll-filmcame1'as;; Fig.-'l shows-asectional view of one ---=end:-ofa -spoolshowing its component parts disassembled at one stage in itsconstruction; Fig. 2 is:a sim ilartview to Fig. 1 showing-the end as afinishedspool';Fig. 3-isa sectional view thereof taken -through"the line3'-3 (Fig.2) and Fig. 4

is-an:endtview -of the' finished spool. Figs. 5 and 6 show respectivelyan 'elevationand a plan view not the key stop;'Figs.' 7.an'd 8 aresectional views -showing the modificationapplied to a spool ofsmaller-=size; while Figs. 9 and 10 are sectional -views of aslightlydifferent construction of the In: all these-views= the referencenumerals 1 and 2' indicate: the barrel of the spool and an gend 'disc,respectively. i

inf-the construction shownin Figsl, 2, 3, and "4, an end disc providedwith a number of "curved-slots or openings '3 which are iormedbyshearing the material of theend-disc along the inner edge of the slotandturning over the material occupying the position of the slot as at 4to form the openings 3. Although only three such slots are here shown itwill be understood that there may be only two or any other number ofslots as may be required. These openings 3 are arranged in the form ofan interrupted annular slot, the diameter across the inner edges of theinterrupted annular slot being slightly greater than the normal diameterof the barrel 1 which is of tubular form, the end of the barrel beingflared as at 5 to allow the end of the barrel to be inserted in theslots or openings 3. It should be noted that in forming the slots oropenings 3 no metal is actually cut clearly shown in Figs. 2 and 3.

formed to have a fiat portion 6 and a depressed portion 7 of the shapeshown, this latter portion receiving the end of the winding key. Thelength of the flat portion, between its curved ends, is approximatelyequal, to the diameter of the flared portion 5 of the barrel 1 so thatwhen the flat portion of the key stop is placed between the end disc andthe end of the barrel the flat portion 6 vof the key stop will he'-clamped in position when the spool is completed. The key stop ispositioned by the turned in edges of the key slot 8 in the end discwhich fit inside the vertical sides of the portion '7 as With the end ofthe barrel and the key stop in position the outeredges 4 of the slots 3are forced back into their original positions in the plane of the enddisc and. thus grip. the flared portion of the barrel tightly. The endof the spoolthen has the form'shown inFigs. 2, 3and 4, which'show oneend of a completed spool. The'other end disc is similarly secured inposition, although of course theend ,disc would have merely, a centralbearing-hole instead of a key slot and no key stop would be provided.

By this method of constructionthe enddiscs, and key stop where fitted,are securely held in their correct positions on the barrel without anyadditional security such as welding or the like and the constructionpossesses great rigidity and mechanical strength.

In the modifiedform of constructionshown ,in Figs. 7 and 8 the method ofconstruction is shown applied-to a spool of smaller size for which thisconstruction is particularly suitable. In this case a central hole, of adiameter slightly less than the external diameter of the barrel, is

formed in each end disc andthe edge 9 of this hole is then turned over,as shown to, allow the end of the barrel to be passed therethrough andthe turned over. edge 9 is thenforced back into its original position inthe plane of the disc so that it grips the barrel and secures the enddisc firmly in position. In the smallest sizes of spool theends of thebarrel extend beyond the outer faces of the end discs, as shown, to formend disc and the edges of the slots which have stub spindles in theusual manner. When the size of the barrel permits, however, the ends ofthe latter may have-inserts 10 pressed therein, as indicated in Figs. 9and 10, these inserts being provided withholes 11 which form a bearingupon which the spool revolves or a key slot for the winding key,respectively. When these inserts are fitted to the spool the end disc issecured flush with the end of the barrel since stub spindles are nolonger required. It should be noted that in this case the end disc issecurely fastened in position on the barrel before the insert is pressedinto position and the latter does not contribute in any way towardssecuring the end disc as in a known construction in which an end cap isforced into the end of the barrel to grip the latter between itself anda deep collar on the end flange.

What we claim asour invention and desire to secure by Letters Patentis:-

l. A method of attaching the end flanges to the barrel ofa spool, of thetype comprising a tubular central barrel and end discs secured thereon,which consists in forming in each end disc a plurality of arcuate slots,arranged in the form of aninterrupted annulus, by shearing the end discalong a line which ultimately forms the inner edge of a slot andsimultaneously turning back the metal occupying the position of a slotwitho'ut'completely removing any material, in-

serting the end of the barrel in the curved slots so formed and thenforcing back the turned back :edges of the slots substantially intotheir original position in the plane of the disc so as to grip the edgeof the end of the tubular barrel between ,the' undeformed part of theend disc and the edges of the slots which have been forced back intoposition.

2. A method of attaching the end flanges of a spool, according toclaim1, wherein the end of the barrel is flared before being inserted in theslots.

'3. In a photographic film spool, a tubular barrel, an end disc securedthereon by shearing and turning back portions of the latter to formslots ,into'which the end of the barrel is inserted and vedges of theslots which have been forced back into position; a key stop formed froma metal blank to have a flat portion and a depressed portion receivingthe end of the winding key, the flat portion having its edge insertedbetween the end disc and the end of the barrel before the turned overedges of the slots in the end disc are forced back into position, sothat the edge of said flat portion is gripped with the end of the barrelbetween the undeformed portion of the been forced back into position.

THOMAS GEORGE BAXENDEN. JOHN ROBERT COLLYEAR.

